Railroad Coupler Knuckle with External Weight Reducing Features

ABSTRACT

A railroad coupler knuckle includes a knuckle body having a tail, a pin hole extending along a pivot axis and a front face configured to transmits the buff forces of the train; a pair of external weight saving pockets on the front face of the knuckle body extending into the knuckle body; an intervening support ridge on the front face of the knuckle body between the pair of weight saving pockets, and wherein the intervening support rib extends along a rib defining plane perpendicular to the pivot access, and wherein the rib defining plane extends through the tail of the body.

BACKGROUND INFORMATION 1. Field of the Invention

The present invention relates to railroad couplings, and more particularly to a railroad coupler knuckle having external weight reducing features.

2. Background Information

A railroad coupler, also called a coupling, is a device for connecting rolling stock, i.e. the railcars, in a train. The general design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximized if all rolling stock can be easily and quickly coupled together. The equipment that connects the couplings to the rolling stock is known as the draft gear.

The “Janney Coupler” is a semi-automatic railway knuckle coupler. The earliest commercially successful version of the semi-automatic knuckle coupler was patented by Eli H. Janney in 1873 bearing U.S. Pat. No. 138,405 which is incorporated herein by reference. Mr. Janney, a major in the Confederate Army during the American Civil War and serving on Gen. Robert E. Lee's staff, was a dry goods clerk post war in Alexandria Virginia, home of the modern day United States Patent and Trademark Office, where he developed his knuckle coupler. The city of Alexandria named one of their streets in his honor, Janney's Lane.

In 1893, satisfied that a semi-automatic knuckle coupler could meet the demands of commercial railroad operations and, at the same time, be manipulated safely, the United States Congress passed the Safety Appliance Act (SAA). Its success in promoting switchyard safety was stunning, as considering between 1877 and 1887, approximately 38% of all rail worker accidents involved coupling, and that percentage fell considerably as the railroads began to replace link and pin couplers with automatic couplers. By 1902, only two years after the SAA's effective date, coupling accidents constituted only 4% of all employee accidents. Coupler-related accidents dropped from nearly 11,000 in 1892 to just over 2,000 in 1902, even though the number of railroad employees steadily increased during that decade. Thus the semi-automatic knuckle coupler has played a critical role in improving railway safety for workers.

In the United Kingdom, where the semi-automatic knuckle coupler is fitted to some rolling stock, mostly for passenger trains, it is also known as a “Buckeye Coupler”, possibly originating from the coupler's manufacture as early as 1890 by the Buckeye Steel Castings company in Columbus, Ohio. The AAR/APTA Type E, Type F, and Type H tightlock couplers are all compatible semi-automatic knuckle couplers, but are employed on specific types rail cars (general freight, tank cars, rotary hoppers, passenger, etc.).

Prior to the formation of the AAR (Association of American Railroads) these types of couplers were known as MCB Couplers (Master Car Builders Association). After 1910 the MCB reconstituted itself into the AAR. In 1913 the American Steel Foundries (ASF) had developed the new Type “D” coupler that was accepted as the standard coupler for the USA, and no new equipment could be built using any other coupler. This standard design ended the market for couplers with a proprietary head design, which were common in the MCB days, to all but those exported from the USA to other countries not governed by the AAR standards. The Interlocking contour of knuckle couplers was the first aspect to be standardized. In the MCB years, prior to about 1910, there were many proprietary “head” designs, and many MCB standard contours, which were constantly evolving and changing (as the approved standard contour for new couplers) every few years.

In about 1910 the producers were all using the then standardized MCB-10 contour, soon to become the AAR-10. In 1930 the AAR Type “D” was improved and became the Type “E”; the contour, however, stayed the same. A few years later the 10 contour was modified into a then optional standard called the 10A contour.

The most modern contour, for a plain Type “E” knuckle coupler, is still the AAR-10 and 10A, which are largely indistinguishable from the 1910 era MCB-10 contour. The same MCB-10 contour has been an approved standard for interchange service for over 100 years, with only the slightest dimensional changes. The Type “H” or “tight-lock” couplers, which are used on passenger-carrying rolling stock, also use slight revisions to the old 10A contour. Type H coupler, also called a “tight-lock” variation, is intended to reduce slack action and improve safety for passenger cars is now under the supervision of the APTA (American Public Transportation Association).

The conventional knuckle currently available is a cast knuckle that includes cored sections, such as disclosed in U.S. Pat. No. 4,605,133. The front core of a knuckle is commonly referred to as the finger core. The finger core is commonly constructed to produce an internal cavity having thin ribs. These ribs made out of the standard grade E cast steel have demonstrated a weakness to the load environment with the development of fatigue and/or hot tear cracks. The fatigue cracks can grow over time and eventually lead to knuckle failure which results in separation of railcars. Separately, internal or external cracks in the knuckle are a cause for replacement of the knuckle. The rear core of a knuckle is commonly referred to as the kidney core. Knuckles can sometimes break within this portion of the knuckle and this has proven to be a very undesirable location for a failure. A failure in this region of the knuckle can lead to knuckle jamming within the coupler body and prevent a change out of a failed knuckle, thereby requiring the entire coupler assembly to be replaced, a very costly repair.

U.S. Pat. No. 5,954,212 discloses a lightweight knuckle for use in an AAR Standard E or F type railroad car couplers. The outer contouring and inner voids of the knuckle are radically changed from an existing AAR Standard knuckle. The nose of the knuckle is provided with a pair of parallel, coplanar flat surfaces between which is a projection which extend outwardly from the flat surfaces and terminates at an outer curved surface which has the same curvature as the corresponding curvature of the existing AAR Standard knuckle. U.S. Pat. No. 6,129,227 discloses a similar lightweight knuckle.

U.S. Pat. No. 8,302,790 discloses a railway coupler knuckle which has a cavity formed inside the tail portion and at least a portion of the transition portion and a first wall extends between surfaces of the cavity adjacent the transition portion.

U.S. Patent Application Publication 2012-0217217 discloses a cast coupler knuckle formed with internal cavities without using a conventional finger core. See also U.S. Pat. Nos. 8,662,327, 8,646,631, 8,631,952, 8,499,819, 8,485,371.

U.S. Pat. Nos. 8,297,455 and 8,381,923 disclose a knuckle for a railway coupler system made without internal voids or cores. Instead, external circular or disc shaped pockets are formed on the front face and tail portion surface to reduce weight. The knuckle is formed by investment casting (a process based upon lost-wax casting).

U.S. Pat. No. 9,038,836 discloses a lightweight, coupler which is constructed from cast austempered ductile iron.

U.S. Pat. No. 9,199,652 discloses a lightweight, fatigue resistant knuckle utilizing improved internal coring and/or rib arrangements using an austempered metal, such as, for example, austempered ductile iron, austempered steel, as well as other austempered metals and austempered metal alloys.

The above identified patents and publications are incorporated herein by reference. There remained a need in the art for railroad coupler knuckles that reduce weight, improve manufacturability and improve fatigue life.

The applicant's prior work set forth in 2017-0240189, now U.S. Pat. No. 10,486,719, addressed many of the deficiencies associated with the prior art and provided a rail road coupler knuckle with external weight reducing features. The '189 application opened up or defines a new class of railroad coupler designs, yet there is improvement that is possible in this newly created coupler “class.” The railroad coupler knuckler of the present invention is within this class in that it meets AAR contour requirements and it includes unique external weight reducing features that strategically reduce weight without compromising strength or fatigue life. The present invention intends to build on the field or knuckle coupler class established by the '189 publication.

SUMMARY OF THE INVENTION

This invention is directed to a railroad coupler knuckle with external weight reducing features. The railroad coupler knuckler of the present invention meets AAR contour requirements and it includes unique external weight reducing features that strategically reduce weight without compromising strength or fatigue life.

The design of the railroad knuckle of the present invention allows for formation of the knuckle through forging techniques and thus allows for the use of a better grade of steel compared to AAR Grade E and such forging processes will yield much higher fatigue life compared to cast knuckles.

One embodiment of the invention provides an E-type coupler knuckle which includes a knuckle body having a tail, a pin hole extending along a pivot axis and a front face configured to transmits the buff forces of the train; a pair of external weight saving pockets on the front face of the knuckle body extending into the knuckle body; an intervening support ridge on the front face of the knuckle body between the pair of weight saving pockets, and wherein the intervening support rib extends along a rib defining plane perpendicular to the pivot access, and wherein the rib defining plane extends through the tail of the body.

One embodiment of the invention provides a coupler knuckle including a knuckle body having a tail, a pin hole extending along a pivot axis and a front face configured to transmits the buff forces of the train; a pair of external weight saving pockets on the front face of the knuckle body extending into the knuckle body; an intervening support ridge on the front face of the knuckle body between the pair of weight saving pockets extending along a rib defining plane; and a tail positioned weight saving pocket on a tail of the knuckle extending along the rib defining plane.

The elements that characterize the present invention are pointed out with particularity in the claims which are part of this disclosure. These and other aspects of the invention, its operating advantages and the specific objects obtained by its use will be more fully understood from the following detailed description in connection with the attached figures.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-B are perspective views of the E-type coupler knuckle according to the present invention;

FIGS. 2A-2E are isometric views of the E-type coupler knuckle of FIGS. 1A-1B;

FIGS. 3A-3D are sectional views of the E-type coupler knuckle of FIGS. 1A-1B;

FIGS. 4A-4B are isometric views of the E-type coupler knuckle of FIGS. 1A-1B;

FIGS. 5A-5C are isometric views of the E-type coupler knuckle of FIGS. 1A-1B.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A conventional E-type coupler knuckle is well known to those of ordinary skill in the art, and is illustrated in applicant's prior work set forth in 2017-0240189, now U.S. Pat. No. 10,486,719, which is incorporated herein by reference.

Similar to a conventional E-type coupler knuckle, the coupler knuckle o 10 of the invention includes a front face 12 which can be described as one of the surfaces of the knuckle that transmits the buff forces of the train. For reference the buff forces are the compressive forces (e.g., the cars coming together) and draft forces are the tensile forces (e.g., the cars moving apart). The nose 14 of the conventional e-type coupler knuckle is the primary contour of the knuckle that allows the coupler to mate with the adjacent coupler (via coupler knuckle rotated 180 degrees about a vertical axis).

The pulling face 16 is the surface of the knuckle 10 that transmits the draft forces through coupler. The throat 18 of the knuckle 10 is the narrow portion on the inside of the knuckle which transitions from the pulling face 16 to the tail 22. The two buffing shoulders 20 work together with the front face 12 to transmit buff forces into the coupler body through cooperating or corresponding surfaces on the coupler body.

The pulling lugs 24 are formed by a combination of a substantially straight surface and a curved or radial surface and each lug 24 engages a corresponding surface on the coupler body to transmit draft forces through the pulling lug 24 into the coupler body. The locking face 26 is a generally flat surface configured to abut the coupler lock when the lock has dropped into the locked or coupled position. In the locked or coupled position the coupler lock is sitting on the lock shelf 28 (discussed below) and the lock in this position resists the moment created by the draft forces.

The tail 22 of the E-type coupler knuckle 10 is a contoured surface that allows the knuckle 10 to pivot between coupled and uncoupled position. Further the top of the tail 22 provides surface for the lock to ride upon as knuckle 10 is pivoted to a position in which the lock drops onto the lock shelf 28 to lock the coupler knuckle 10 in position. A tail pad is opposite the tail lock and resists the moment created by the buff forces. The tail pad may be pronounced (larger) to reduce slack in the knuckle 10. The tail stop 30 is the surface of the knuckle 10 that engages with the coupler wall in the buff mode and may be considered the portion of the knuckle which transitions from the tail 22 to the spine 32.

The coupler knuckle 10 includes a hub feature 34 around the pin. It is meaningful to note that if knuckle 10 works correctly (i.e. it is not worn) then no buff or draft forces are transmitted through the pin itself. The knuckle 10 includes a pivot pin hole 36 configured to receive a pivot pin there through, about which the coupler 10 can rotate. The pivot pin hole 36 may include relief cuts or grooves to prevent binding of the pin. The knuckle 10 further includes pin protector surfaces 38 that are configured such that they cooperate with coupler components to transmit forces if the knuckler 10 starts to wear. In other words the surfaces 38 are configured to protect the pin.

The coupler knuckle 10 includes a heel 40 that may be considered as the transition from the front face 12 to the hub feature 34. Further, a thrower pad 42 is included in a bottom portion of knuckle 10 and this pad 42 cooperates with a feature of the thrower that moves with upward lifting of the lock to push against the thrower pad 42 to pivot the knuckle 10 open. The thrower pivots the knuckle 10 as the lock is lifted out of the locked position.

The coupler knuckle 10 includes a flag hole 44 which is configured to receive a safety indicator flag, which gives a universal visual indication not to couple to the car. The flag is used on a leading car when work is being conducted in an area in which coupling of the train of cars must be avoided. As noted above the knuckle 10 includes a lock shelf 28 which is configured to hold the lock when it has dropped into the locked or in the secured position. Finally the E-type knuckle 10 includes a spine 32 which is considered the transition surface from the tail stop 30 to the hub feature 10.

The E-type knuckle 10 according to one aspect of the present invention includes two external weight saving features 50 or pockets with intervening support ridge 52 on the front face 12 of the knuckle 10. The bottom of the weight saving features or pockets 50 for this embodiment are flat. The pockets 50 have a width measured generally along the pivot axis and perpendicular to the rib defining plane, and wherein the width of each pocket decreases moving in a direction away from the pivot axis. The a rate of decrease of the width of each pocket 52 is less on a flag hole 44 side of the pivot axis (36) than the opposing side.

The intervening support rib 52, also called a ridge, extends along a rib defining plane perpendicular to the pivot access, and wherein the rib defining plane extends through the tail 22 of the body of the knuckle 30. The intervening support ridge 52 extends horizontally across the front face 12. The intervening support rib or ridge 52 has a width measured generally along the pivot axis through hole 36 and perpendicular to the rib defining plane, wherein the intervening support ridge 52 is substantially (+/−10%) uniform width along the rib defining plane.

The E-type knuckle 10 according to one aspect of the present invention includes a tail positioned weight saving features 54 or pocket on the tail 22 of the knuckle 10. The tail positioned weight saving pocket 54 extends along the rib defining plane. The pocket 54 extends horizontally across the tail 22. The pocket 54 has a width measured generally along the pivot axis through hole 36 and perpendicular to the rib defining plane, wherein the pocket 54 is substantially (+/−10%) uniform width along the rib defining plane (it is noted the width of the pocket 54 is not including the curved end portions of the pocket 54 on either side of the tail 22)

Within the meaning of this application an external weight saving pocket 50 and 54 is a feature extending into the knuckle 10 from an exterior surface of the knuckle 10, and is a structure that is capable of being formed in a forging operation or casting operation without requiring an internal core. The design of the railroad knuckle 10 of the present invention allows for formation of the knuckle 10 through forging techniques and thus allows for the use of a better grade of steel compared to AAR Grade E and such forging processes will yield much higher fatigue life compared to cast knuckles.

The weight saving features 52 extend at least 70% of the width of the front face 12, at least between the axis of the pin hole 36 and the axis of the flag hole 44 in a front elevation view (technically the front elevation view is a vertical viewing plane perpendicular to the buff and draft forces).

The forged knuckle 10 shown in the figures exhibits a weight of less than 90 lbs (about 88 lbs) compared with a forged knuckle without these features (FIGS. 1A-E) of about 105 lbs, and this knuckle 10 is shown to have extended fatigue life over a comparable core cast knuckle.

While the invention has been shown in several particular embodiments it should be clear that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the present invention is defined by the appended claims and equivalents thereto. 

What is claimed is:
 1. A coupler knuckle comprising: A knuckle body having a tail, a pin hole extending along a pivot axis and a front face configured to transmits the buff forces of the train; A pair of external weight saving pockets on the front face of the knuckle body extending into the knuckle body; An intervening support ridge on the front face of the knuckle body between the pair of weight saving pockets, wherein the improvement comprises Wherein the intervening support ridge extends along a rib defining plane perpendicular to the pivot access, and wherein the rib defining plane extends through the tail of the body.
 2. The coupler knuckle according to claim 1, wherein the intervening support ridge has a width measured generally along the pivot axis and perpendicular to the rib defining plane, wherein the intervening support ridge has a substantially uniform width along the rib defining plane.
 3. The E-type coupler knuckle according to claim 2 wherein the intervening support ridge extends horizontally across the front face.
 4. The E-type coupler knuckle according to claim 2 wherein the pockets have a width measured generally along the pivot axis and perpendicular to the rib defining plane, and wherein the width of each pocket decreases moving in a direction away from the pivot axis..
 5. The E-type coupler knuckle according to claim 4 wherein the a rate of decrease of the width of each pocket is less on a flag hole side of the pivot axis than the opposing side.
 6. The E-type coupler knuckle according to claim 2 further including a tail positioned weight saving pocket on the tail of the knuckle.
 7. The E-type coupler knuckle according to claim 6 wherein the tail positioned weight saving pocket extends along the rib defining plane.
 8. The E-type coupler knuckle according to claim 6 wherein the tail positioned weight saving pocket extends horizontally across the tail.
 9. The E-type coupler knuckle according to claim 6 wherein the tail positioned weight saving pocket has a width measured generally along the pivot axis and perpendicular to the rib defining plane, wherein the tail positioned weight saving pocket is substantially uniform width along the rib defining plane.
 10. The E-type coupler knuckle according to claim 1 wherein the coupler knuckle is forged.
 11. The E-type coupler knuckle according to claim 1 wherein the coupler knuckle weighs less than 90 lbs.
 12. A coupler knuckle comprising: A knuckle body having a tail, a pin hole extending along a pivot axis and a front face configured to transmits the buff forces of the train; A pair of external weight saving pockets on the front face of the knuckle body extending into the knuckle body; An intervening support ridge on the front face of the knuckle body between the pair of weight saving pockets extending along a rib defining plane; and a tail positioned weight saving pocket on a tail of the knuckle extending along the rib defining plane.
 13. The E-type coupler knuckle according to claim 12 wherein the coupler knuckle is forged.
 14. The E-type coupler knuckle according to claim 12 wherein the coupler knuckle weighs less than 90 lbs.
 15. The coupler knuckle according to claim 12, wherein the intervening support ridge has a width measured generally along the pivot axis and perpendicular to the rib defining plane, wherein the intervening support ridge has a substantially uniform width along the rib defining plane.
 16. The E-type coupler knuckle according to claim 15 wherein the intervening support ridge extends horizontally across the front face.
 17. The E-type coupler knuckle according to claim 15 wherein the pockets have a width measured generally along the pivot axis and perpendicular to the rib defining plane, and wherein the width of each pocket decreases moving in a direction away from the pivot axis..
 18. The E-type coupler knuckle according to claim 17 wherein the a rate of decrease of the width of each pocket is less on a flag hole side of the pivot axis than the opposing side.
 19. The E-type coupler knuckle according to claim 12 wherein the tail positioned weight saving pocket extends horizontally across the tail.
 20. The E-type coupler knuckle according to claim 12 wherein the tail positioned weight saving pocket has a width measured generally along the pivot axis and perpendicular to the rib defining plane, wherein the tail positioned weight saving pocket is substantially uniform width along the rib defining plane. 